Refreshed motor - poor accelaration

[SavedByGrace]

Hi guys - just finished the rebuild on an 03 2500 5.7 4x4 last week..

PO spun a rod bearing and I put in good replacement crank (journals exactly on factory spec)
new bearings all round
new rings
new plugs
new head gaskets and head bolts

I cleaned the throttle body REAL well (it was pretty clean) -

light hone - bores were excellent.. she starts and idles SUPER smooth - I can reach 50-70 on the highway but low down shes superbly mushy -

I cleaned everything - incl throttle body.. apart form the 4x4 light staying on when shes in 2H everything else seems fine - i reset codes and she passed smog so no pending issues.

I had my ph connected to the obd port and while cruising around 30mph near floored it up to about 70 mph and on the hp gauge the max reading was 135hp?? Not saying its necessarily accurate -

Any ideas?

Im going to disconnect the neg cable and wait 5 minutes, and then do the throttle slowly to the floor and back and see if that helps..

 

[SavedByGrace]

I guess i can do a fuel psi test - seems the filter can cause low pressure / performance. Ill check the idle vac and report back

 

[HemiLonestar]

That doesn't sound accurate at all, even with the amount of parasitic loss the RFE is good for, you should still be at the 270hp mark to the wheels bone stock. You stock fuel pressure on an 03 is right about 48psi (I believe 47-51 is the "official" range; 04 and on they upped it 10psi, no clue as to why).

 

[Fast69Mopar]

Do you have a good scan tool available? Take a look at the cam/crank sync and also look at the timing advance to see what your base idle timing is and advance while under a load.

 

[Bloody_Knuckles]

Clogged catalytic converter?

 

[SavedByGrace]

Do you have a good scan tool available? Take a look at the cam/crank sync and also look at the timing advance to see what your base idle timing is and advance while under a load.

I have dash command - an android app.. paid for it - has a ton of gauges you can view.. ill try and see this week what i can fnd - been crazy busy with work unfortunately..

thanks-

dont think its a blocked cat cos i can get up to 70mph without too much difficulty.. guess I could bypass temporarily and see if i dont get some info-